EP2006572B1 - Device for mass compensation for a reciprocating piston combustion engine - Google Patents

Description

The invention relates to a device for mass balance for a reciprocating internal combustion engine having the features of the preamble of patent claim 1.

The technical environment, for example, the German patent application DE 102 57 562 A1 referenced, in which a mass balance for a reciprocating internal combustion engine is described in which the two counter-rotating balance shafts are arranged largely horizontally next to each other, geodetically below the crankshaft of the reciprocating internal combustion engine.

• ⇒ dass das Massenausgleichsgetriebe über ein Getriebe mit der Kurbelwelle der Brennkraftmaschine verbunden ist,
• ⇒ dass eine erste Ausgleichswelle des Massenausgleichsgetriebes über eine Zahnradstufe mit einer zweiten Ausgleichswelle verbunden ist und
• ⇒ dass eine in einer Ölwanne der Brennkraftmaschine angeordnete Ölpumpe an die zweite Ausgleichswelle gekoppelt ist und dass eine zusätzliche zu- oder abschaltbare Ölpumpe an die erste Ausgleichswelle gekoppelt ist.

In order to prevent a gear rattle a generic device for mass-force and / or torque compensation for a reciprocating internal combustion engine, is in the German utility model, the DE 202 01 006 U1 proposed the following type:

• ⇒ that the mass balancing transmission is connected via a transmission with the crankshaft of the internal combustion engine,
• ⇒ that a first balance shaft of the mass balance gear is connected via a gear stage with a second balance shaft and
• ⇒ that arranged in an oil pan of the internal combustion engine oil pump is coupled to the second balance shaft and that an additional on or off switchable oil pump is coupled to the first balance shaft.

In order to reduce the space for a generic device for mass and / or torque compensation of a reciprocating internal combustion engine is in the European patent application EP 1 031 760 A1 , from which this invention proceeds, proposed that a balancer shaft is provided with two rotatably connected to it gears, one of which is for driving the balancer shaft with a formed on the crankshaft gear and the other is formed with a balance weight and a Further gear drives, which forms the balance shaft formed with a further balance weight and is coaxially mounted thereon with the crankshaft, wherein the balance shafts are spaced from each other radially and perpendicular to the engine center line.

Although the prior art, from which this invention proceeds, has no principal disadvantages, the invention is based on the object to reduce the space again.

This object is solved by the features in the characterizing part of patent claim 1.
Due to the suitable design of the balance weights with a vertical arrangement of the balance shafts, it is possible to mesh the opposing balance weights in one another. This is a significantly reduced center distance and thus a reduced height compared to the known from the prior art concepts of the entire device for Mass compensation for a reciprocating internal combustion engine possible. Due to the reduced height further weight reduction for the entire device can be displayed. Further, the compensation of a second-order mass momentum is possible by the height offset of the two counter-rotating balance shafts.

The drive by means of the already present in the lubricant pump and only to be extended drive shaft is also space and cost compared to a separate drive shaft from the front chain drive ago.

The embodiment according to claim 2 allows further design freedom.

With the maximum spacing of the axes of rotation of the balance shafts according to claim 3, the maximum compensation of the second order mass moment is achieved.

The embodiments according to claims 5 and 6 are particularly preferred embodiments.

Fig. 1

zeigt schematisch die Lage von zwei Ausgleichswellen zu vier unterschiedlichen Kurbelwellenwinkeln, gemäß dem Stand der Technik.

Fig. 2

zeigt schematisch die Lage von zwei erfindungsgemäß angeordneten Ausgleichswellen zu vier unterschiedlichen Kurbelwellenwinkeln.

Fig. 3

zeigt eine dreidimensionale Aufsicht auf zwei erfindungsgemäß angeordnete Ausgleichswellen.

Fig. 4

zeigt eine dreidimensionale Aufsicht auf eine Kurbelwelle und zwei über eine Kette angebundene Ausgleichswellen.

Fig. 5

zeigt eine Seitenansicht auf die Kurbelwelle und die zwei, über die Kette angebundenen Ausgleichswellen.

Fig. 6

zeigt schematisch ein zweites, besonders bevorzugtes Ausführungsbeispiel mit zwei erfindungsgemäß angeordneten Ausgleichswellen.

In the following the invention is explained in more detail with reference to two particularly preferred embodiments in six figures.

Fig. 1

schematically shows the position of two balance shafts to four different crankshaft angles, according to the prior art.

Fig. 2

schematically shows the position of two balance shafts according to the invention arranged at four different crankshaft angles.

Fig. 3

shows a three-dimensional view of two according to the invention arranged balance shafts.

Fig. 4

shows a three-dimensional view of a crankshaft and two connected via a chain balancing shafts.

Fig. 5

shows a side view of the crankshaft and the two, connected via the chain balancing shafts.

Fig. 6

schematically shows a second, particularly preferred embodiment with two balance shafts arranged according to the invention.

Below, the same reference numerals apply to the same components in all figures.

Fig. 1 schematically shows in a front view a first balance shaft 3 with a first balance weight 3 'and a second balance shaft 4 with a second balance weight 4'. The balance shafts 3, 4 are arranged vertically one above the other and shown at four different crankshaft angles, 0 ° CA (crank angle), 45 ° CA, 90 ° CA and 135 ° CA, whereby only the 0 ° CA position is numbered. In the Fig. 1 illustrated balance shafts 3, 4 correspond to the prior art and have such a large vertical center distance, that the balance weights 3 ', 4' are spaced from each crankshaft angular position.

In contrast, shows Fig. 2 schematically, the first and the second balance shaft 3, 4 in an arrangement according to the invention. As to the different crankshaft angles 0 ° KW, 45 ° KW, 90 ° KW and 135 ° KW too is recognize, the first and the second balance shaft 3, 4 are arranged with such a small center distance to each other, that the first and the second balance weight 3 ', 4' mesh with each other. The inventive arrangement of the required space for the device for mass balance for a reciprocating internal combustion engine is advantageously minimized significantly.

Fig. 3 shows a three-dimensional view of two inventively arranged balance shafts 3, 4 with their balance weights 3 ', 4'. Also with reference to this specific structural design is to see how small the center distance of the two balance shafts 3, 4 is executed, whereby the minimum size is achieved.

Fig. 4 shows a three-dimensional view of a crankshaft 2 with two connected via a chain 9 balance shafts 3, 4. The first balance shaft 3 with the first balance weight 3 'is driven by the crankshaft 2 with a double crankshaft speed. The second balance shaft 4 with the second balance weight 4 'can be driven in opposite directions by a first spur gear pair 7 (spur gear stage) from the first balance shaft 3. An engine high-axis direction H and an engine transverse axis direction Q are schematically represented by double arrows.

Fig. 5 shows the same arrangement Fig. 4 again in a side view. The center distance of the two balance shafts 3, 4 is marked with a. In the Fig. 4 and 5 is a special geometric case shown, in which the axial distance a corresponds to a lifting height of a piston, not shown. For this center distance, the second-order mass moments are completely eliminated. The center distance is shown enlarged for better illustration, so that the balance weights 3 ', 4' in the Fig. 4 and 5 not according to the invention comb with each other.

Fig. 6 schematically shows a particularly preferred embodiment of the inventive arrangement.

In Fig. 6a is an end view of the inventive arrangement of the first and second, in Fig. 6b in a side view shown balance shafts 3, 4, shown. The balance shafts 3 ', 4' are arranged as black circle segments on the balance shafts 3, 4. The vertically stacked balance shafts 3, 4 also have an offset in the engine transverse axis direction Q in this exemplary embodiment.

In Fig. 6b schematically, the crankshaft 2 is shown by an arrow, with the over the chain 9, a drive shaft 5 of a lubricant pump 6 is driven. A direction of rotation of the drive shaft 5 is shown with a rotary arrow. The drive shaft 5 in turn drives the second balance shaft 4 with the second balance weight 4 'via a second spur gear pair 8 with a suitable gear ratio. Via a third spur gear pair 10, the second balance shaft 4 drives the first balance shaft 3 with the first balance shaft weight 3 '. The opposite directions of rotation of the balance shafts 3, 4 are in turn shown schematically by rotary arrows. The speed of the balance shafts 3, 4 corresponds to twice the crankshaft speed.

The drive of the balance shafts 3, 4 by means of the already present in the lubricant pump 6 and only to be extended drive shaft 5 is advantageously space and cost compared to a separate drive shaft from the front chain drive forth. The advantages of this particularly preferred embodiment are the compact and lightweight design, a minimum number of parts, which reduces the cost and the package.

The drive of one of the two balance shafts 3, 4 is preferably carried out by a spur gear, a chain or belt drive or a combination of these possibilities of the crankshaft 2. The direction of rotation of the geodetically overhead balancing shaft 3, 4 is selected so that it corresponds to the crankshaft rotation direction. The two balance shafts 3, 4 and the connecting, z. B. spur gear (synchronous step) form together with a balance shaft housing a balance shaft module. Flexibility in the casting process (die casting) results in cost and weight advantages.

Due to the height offset of the two counter-rotating balance shafts 3, 4, the compensation of a second order mass moment is possible. By the axial distance (a) of the two balance shafts 3, 4, the degree of compensation with respect to the second-order moments of inertia is determined. Full compensation is achieved with a height difference in the region of the connecting rod length of the internal combustion engine.

Due to the offset in height opposing force in the amplitude minimum of the total force produced during operation of the reciprocating internal combustion engine results in a smaller change in distance (due to the bearing clearance) of the two axes of rotation of the balance shafts 3, 4, as compared to a horizontal arrangement to each other. This results in a lower rotational backlash in the synchronizing step, whereby acoustic advantages are achieved in an advantageous manner.

LIST OF REFERENCE NUMBERS

1.

contraption

Second

crankshaft

Third

first balance shaft

3 '

first balance weight

4th

second balance shaft

4 '

second balance weight

5th

Through shaft

6th

lubricant pump

7th

first spur gears

8th.

second spur gears

9th

Chain

10th

third spur gears

Claims (6)

1. A balancing device (1) for a reciprocating internal combustion engine comprising at least one piston driven by a crankshaft (2) via a connecting rod, wherein the device (1) has a first balancer shaft (3) with a first balancing weight (3') and a second balancer shaft (4) with a second balancing weight (4'), disposed in the vertical axial direction (H) of an internal combustion engine, wherein at least one balancer shaft(3,4) is drivable in rotation by the crankshaft (2) at double speed and the other balancer shaft (4,3) is drivable at double speed by the crankshaft (2) in the opposite direction of rotation to that of the balancer shaft (3,4),
   characterised in that the first and the second balancer shaft (3, 4) are disposed so that when the balancer shafts (3, 4) are rotating the first and the second balancing weight (3', 4') mesh in one another and wherein the first or the second balancer shaft (3,4) is driven via the driving shaaft of a lubricant pump (6) drivable by the crankshaft (2).
2. A device according to claim 1,
   characterised in that the balancer shafts (3, 4) are offset from one another in a transverse axial direction (Q) of an internal combustion engine.
3. A device according to claim 1 or claim 2,
   wherein the balancer shafts rotate around an axis of rotation, characterised in that the axes of rotation in the vertical axial direction (H) of the internal combustion engine are separated from one another by up to a stroke of a piston (a).
4. A device according to any of claims 1 to 3,
   characterised in that a balancer shaft (3, 4) is drivable by the other shaft (4, 3) via meshing first radial toothed wheels (7).
5. A device according to any of claims 1 to 3,
   characterised in that the first or the second balancer shaft (3,4) is drivable by the driving shaft (5) via meshing second cylindrical gearwheels.
6. A device according to any of claims 1 to 5,
   characterised in that the first or the second balancer shaft (3,4) or the driving shaft (5) is drivable by the crankshaft (2) via meshing gearwheels or a chain (9).

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